EGFR signaling-dependent inhibition of glioblastoma growth by ginsenoside Rh2

Glioblastoma is the most common and most aggressive malignant primary brain tumor in humans, accounting for 52 % of all functional tissue brain tumor cases and 20 % of all intracranial tumors. The typical treatment involves a combination of chemotherapy, radiation, and surgery, whereas it still achieves fairly poor patient survival. Ginsenoside Rh2 has been reported to have a therapeutic effect on some tumors, but its effect on glioblastoma has not been extensively evaluated. Here, we show that ginsenoside Rh2 can substantially inhibit the growth of glioblastoma in vitro and in vivo in a mouse model. Moreover, the inhibition of the tumor growth appears to result from combined effects on decreased tumor cell proliferation and increased tumor cell apoptosis. Further analyses suggest that ginsenoside Rh2 may have its antiglioblastoma effect through inhibition of the epidermal growth factor receptor (EGFR) signaling pathway in tumor cells. In a lose-of-function experiment, recombinant EGFR was given together with ginsenoside Rh2 to the tumor cells in vitro and in vivo, which completely blocked the antitumor effects of ginsenoside Rh2. Thus, our data not only reveal an anti-glioblastoma effect of ginsenoside Rh2 but also demonstrate that this effect may function via inhibition of EGFR signaling in glioblastoma cells.

Permeability of the blood-tumor barrier is enhanced by combining vascular endothelial growth factor with papaverine

This study aims to determine the effects of vascular endothelial growth factor (VEGF), papaverine (PA), and the combination of VEGF and PA on the permeability of the blood-tumor barrier (BTB) and to determine possible molecular mechanisms contributing to the effects. In the rat C6 glioma model, the extravasation of Evans blue (EB) through the BTB was increased significantly by VEGF and PA. VEGF-induced and PA-induced increase of EB extravasation was further increased after combining VEGF with PA infusion. Transmission electron microscopy (TEM) showed that the combination of VEGF and PA not only opened tight junctions (TJ) dramatically but increased the presence of pinocytotic vesicles of brain microvascular endothelial cells (BMECs) significantly. Meanwhile, the downregulation of the TJ-associated proteins occludin and claudin-5 and the upregulation of the caveolae structure proteins caveolin-1 and caveolin-2 caused by the combination of VEGF and PA were observed by Western blot and immunohistochemistry, which were more remarkable than those by the two strategies separately. In addition, after VEGF and PA infusion, the results of radioimmunoassay, Western blot, and enzyme-linked immunosorbent assay (ELISA) revealed a significant increase in expression levels of cGMP and protein kinase G-1 (PKG-1) and the activation of nuclear factor-κB (NF-κB) p65. This study demonstrates that combination of VEGF and PA can increase the permeability of the BTB by a paracellular pathway (downregulation of occludin and claudin-5) and a transcellular pathway (upregulation of caveolin-1 and caveolin-2) and that the cGMP/PKG/NF-κB signal pathway might be involved in the modulation process.

MiR-320a down-regulation mediates bladder carcinoma invasion by targeting ITGB3

To investigate whether the miR-320a could regulate bladder cancer cells invasion by down-regulation of ITGB3. Real-time quantitative PCR was applied to evaluate the expression level of miRNA-320a in bladder transitional cell carcinomas (TCC) and normal bladder transitional cell (NBTC) samples. The invasion ability of miR-320a in TCC T24 cells was analyzed by Transwell assay after pre-miR-320a or anti-miR-125b transfection. For the invasion mechanism analysis of miR-320a on T24 cells, TargetScan, PicTar and miRBase were used to predict the possible target gene of miR-320a. Luciferase activities assay and western blot were used to reveal the predicted target gene of miR-320a were direct and specific. RNA interference technology was used to confirm the invasion inhibition of miR-320a was directly induced by ITGB3. Our study showed that miR-320a was down-regulated in human TCC specimens compared to that in NBTC specimens. Over-expression of miR-320a in T24 cells inhibited TCC invasion and this inhibitory effect on T24 cells could be restore by miR-320a knocked down. Mechanism analysis revealed that ITGB3 was a direct and specific target of miR-320a. The advanced effect of anti-miR-320a on TCC cell invasion was mediated by expression silence of ITGB3. In summary, aberrantly expressed miR-320a contribute to T24 cells invasion partly through directly down-regulating ITGB3 protein expression in TCC and this miRNA signature offers a novel potential therapeutic strategy for TCC.

Genetic variations in MOV10 and CACNB2 are associated with hypertension in a Chinese Han population

Human hypertension is a complex, multifactorial disease. Multiple variants associated with hypertension have been identified in the large numbers of genome-wide association studies, meta-analysis, and case-control studies. The present study investigated the association between the single nucleotide polymorphisms (SNPs) of five candidate genes and the susceptibility and prognosis of hypertension in a Chinese Han population. A hospital-based case-control study in a Chinese Han population was carried out, including 500 hypertension patients and 506 healthy controls. The five SNP markers were detected using the Sequenom MassArray(®) iPLEX System. The association of genotypes with susceptibility to hypertension was analyzed using odds ratio, with 95% confidence interval and logistic regression. All five variants conformed to Hardy-Weinberg proportions in the controls. No significant differences were noted in the genotype distributions for AGTR1, PRRC2A, and CALCA polymorphisms in patients with hypertension (N = 500) and healthy controls (N = 506). SNP rs2932538, a variant in MOV10, was found to be significantly associated with an increased risk of hypertension. However, SNP rs4373814, a variant in CACNB2, showed a relevant association with a decreased risk of hypertension. In conclusion, the results of our case-control study confirmed the significant association of the SNP rs2932538 in MOV10 and SNP rs4373814 in CACNB2 with an increased risk of hypertension in a Chinese Han population, suggesting that the SNP rs2932538 may be a poor prognostic indicator for hypertension, while SNP rs4373814 may be a good prognostic indicator for hypertension in the same region. However, our findings need to be replicated in larger epidemiological and functional studies.

Light-controlled astrocytes promote human mesenchymal stem cells toward neuronal differentiation and improve the neurological deficit in stroke rats

Astrocytes are key components of the central nervous system (CNS) and release factors to support neural stem cell proliferation, differentiation, and migration. Adenosine 5'-triphosphate (ATP) is one of the key factors released upon activation of astrocytes that regulates the neural stem cell's function. However, it is not clear whether ATP derived from the depolarized astrocytes plays a vital role in promoting the neuronal differentiation of mesenchymal stem cells (MSCs) in vitro and in vivo. Herein, for the first time, we co-cultured MSCs with light-stimulated-channelrhodopsin-2 (ChR2)-astrocytes, and observed that the neuronal differentiation of MSCs was enhanced by expressing more neuronal markers, Tuj1 and NeuN. The ChR2-astrocyte-conditioned medium also stimulated MSCs differentiating into neuronal lineage cells by expressing more Tuj1 and Pax6, which was blocked by the P2X receptor antagonist, TNP-ATP. Then we found that light-depolarization of astrocytes significantly increased ATP accumulation in their bathing medium without impairing the cell membrane. We further found that ATP up-regulated the Tuj1, Pax6, FZD8 and β-catenin mRNA levels of MSCs, which could be reversed by application of TNP-ATP. Together these in vitro data provided convergent evidence that ATP from light-depolarized-astrocytes activated the wnt/β-catenin signaling of MSCs through binding to the P2X receptors, and promoted the neuronal differentiation of MSCs. Finally but importantly, our study also demonstrated in stroke rats that light-controlled astrocytes stimulated endogenous ATP release into the ischemic area to influence the transplanted MSCs, resulting in promoting the MSCs towards neuronal differentiation and improvements of neurological deficit.

Postantibiotic effect and postantibiotic sub-minimum inhibitory concentration effect of valnemulin against Staphylococcus aureus isolates from swine and chickens

The postantibiotic effect (PAE) and postantibiotic sub-minimum inhibitory concentration (MIC) effect (PA-SME) of valnemulin against Staphylococcus aureus were investigated in vitro using a spectrophotometric technique and classic viable count method. A standard curve was constructed by regression analysis of the number of colonies and the corresponding optical density (OD) at 630 nm of the inoculum. After exposure to valnemulin at different concentrations for an hour, the antibiotic was removed by centrifuging and washing. The PA-SMEs were measured after initial exposure to valnemulin at 4 × the MIC, and then, valnemulin was added to reach corresponding desired concentrations in the resuspended culture. Samples were collected hourly until the culture became turbid. The results were calculated by converting the OD values into the counts of bacteria in accordance with the curve. The MIC of valnemulin against eight strains was identically 0.125 μg ml(-1) . The mean PAEs were 2.12 h (1 × MIC) and 5.06 h (4 × MIC), and the mean PA-SMEs were 6.85 h (0.1 × MIC), 9.12 h (0.2 × MIC) and 10.8 h (0.3 × MIC). The results showed that the strains with identical MICs exhibited different PAEs and PA-SMEs. Valnemulin produced prolonged PAE and PA-SME periods for Staph. aureus, supporting a longer dosing interval while formulating a daily administration dosage.

SIGNIFICANCE AND IMPACT OF THE STUDY

In this study, valnemulin demonstrated prolonged postantibiotic effects and postantibiotic sub-MIC effects on strains of Staphylococcus aureus. The strains with identical MICs of valnemulin exhibited different PAEs and PA-SMEs. Staphylococcus aureus isolated from different species has little impact on the postantibiotic effect of valnemulin. The result suggests a longer dosing interval while formulating a daily administration dosage, and it may play a valuable role of valnemulin in treating Staph. aureus infections in animals.

First Report of Leaf Blight in Chinese Hickory (Carya cathayensis) Caused by Alternaria petroselini in China

Chinese hickory (Carya cathayensis) is one of the important economic forest crops in Zhejiang and Anhui Provinces, China. In 2012, nearly 40% of hickory orchards and 6.8% of hickory trees were affected by leaf blight in Zhejiang. Initial symptoms consisted of small, brown, water-soaked lesions, which subsequently enlarged and developed a black sporulating necrotic center surrounded by a chlorotic halo. Infected leaf samples collected from 25 different orchards in Lin'an and 13 different orchards in Chun'an were surface sterilized with 1.5% sodium hypochlorite for 1.5 min, rinsed in water, plated on 2% potato dextrose agar (PDA), and incubated at 25°C in the dark for 1 week. Single conidium cultures were consistently isolated and cultured on PDA and V8 agar for morphological characterization (1,3). On both agar media, colonies were dark olive brown with smooth margins and concentric rings of sporulation. Conidia were solitary, darkly pigmented, predominantly ovoid-subsphaeroid, and 23 to 52 × 13 to 23 μm with up to six or seven transepta and one to three longisepta. The ribosomal internal transcribed spacers ITS1 and ITS2 of 10 isolates were amplified using primers ITS1/ITS4 on DNA extracted from mycelium and nucleotide sequences showed 100% similarity to that of A. petroselini (GenBank Accession Nos. AY154685.1 and EU807868.1). To confirm pathogenicity, 10 uninfected leaves from each of 10 C. cathayensis trees were sprayed either with a conidia suspension (10⁵ conidia per ml) or with distilled water only to serve as an un-inoculated control. Leaves were subsequently wrapped in plastic bags to retain moisture, and incubated for 48 h. After 1 week, 8 of 10 isolates caused lesions identical to those initially described whereas no symptoms developed on water inoculated leaves. Cultures reisolated from lesions and cultured on PDA exhibited morphological characteristics identical to A. petroselini (1,2,3), confirming Koch's postulates. To our knowledge, this is the first report of leaf blight in C. cathayensis, and this identification would allow producers to identify for appropriate management practices. References: (1) P. M. Kirk et al. The Dictionary of the Fungi, 10th edition, page 159. CABI Bioscience, UK, 2008. (2) B. M. Pryor et al. Mycologia 94:49, 2002. (3) E. G. Simmons. Alternaria: An Identification Manual. CBS Fungal Biodiversity Centre, Utrecht, The Netherlands, 2007.

Mycoplasma gallisepticum and Escherichia coli mixed infection model in broiler chickens for studying valnemulin pharmacokinetics

A Mycoplasma gallisepticum-Escherichia coli mixed infection model was developed in broiler chickens, which was applied to pharmacokinetics of valnemulin in the present experiment. The velogenic M. gallisepticum standard strain S6 was rejuvenated to establish the animal model, and the wild E. coli strain O78 was injected as supplementary inoculum to induce chronic respiratory disease in chickens. The disease model was evaluated based on its clinical signs, histopathological examination, bacteriological assay, and serum plate agglutination test. The pharmacokinetics of valnemulin in infected chickens was determined by intramuscular (i.m.) injection and oral administration (per os, p.o.) of a single dose of 10 mg/kg body weight (BW). Plasma samples were analyzed by liquid chromatography-tandem mass spectrometry. The plasma concentration-time curve of valnemulin was analyzed using the noncompartmental method. After the i.m. administration, the mean values of Cmax , Tmax , AUClast , MRT, CLβ /F, Vz /F, and t1⁄2β , were 27.94 μg/mL, 1.57 h, 171.63 μg·h/mL, 4.51 h, 0.06 L/h/kg, 0.56 L/kg, and 6.50 h, respectively. By contrast, the corresponding values after p.o. administration were 5.93 μg/mL, 7.14 h, 47.60 μg·h/mL, 9.80 h, 0.22 L/h/kg, 3.35 L/kg, and 10.60 h. The disposition of valnemulin was retarded in infected chickens after both modes of extravascular administration as compared to the healthy controls. More attention should be given to monitoring the therapeutic efficacy and adverse effects of mixed infection because of higher required plasma drug concentration and enlarged AUC with valnemulin treatment.

HER2 status in gastric cancers: a retrospective analysis from four Chinese representative clinical centers and assessment of its prognostic significance

BACKGROUND

HER2 has a predictive value in gastric cancer. However, its association with prognosis remains uncertain. The aim of our study was to estimate the HER2-positive rate in Chinese gastric cancers, compare the classical fluorescence in situ hybridization (FISH) method with the novel bright-field dual color silver-enhanced in situ hybridization (DSISH) detection system, and evaluate the relationship between the HER2 status and prognosis.

PATIENTS AND METHODS

Seven hundred and twenty-six resected gastric cancers separately from four clinical centers in China were examined for HER2 by immunohistochemistry (IHC), FISH, and DSISH.

RESULTS

The HER2-positive rate was 13%. The consistency between FISH and DSISH results was high (99%; κ = 0.958; P < 0.001). Tumor heterogeneity and polysomy were the main reasons for inconsistency. There was no significant difference in the 3-year overall survival (OS) between HER2-positive and -negative patients (P = 0.959). Multivariate analysis showed that HER2 was not an independent prognostic factor.

CONCLUSION(S)

HER2 overexpression and amplification occur in a significant number of Chinese gastric cancer patients. Given the obvious advantages and high consistency with FISH, DSISH was superior for evaluating HER2 amplification in gastric cancer. HER2 was not a prognostic factor for gastric cancer in our study.

HER2 status in gastric cancers: a retrospective analysis from four Chinese representative clinical centers and assessment of its prognostic significance

BACKGROUND

HER2 has a predictive value in gastric cancer. However, its association with prognosis remains uncertain. The aim of our study was to estimate the HER2-positive rate in Chinese gastric cancers, compare the classical fluorescence in situ hybridization (FISH) method with the novel bright-field dual color silver-enhanced in situ hybridization (DSISH) detection system, and evaluate the relationship between the HER2 status and prognosis.

PATIENTS AND METHODS

Seven hundred and twenty-six resected gastric cancers separately from four clinical centers in China were examined for HER2 by immunohistochemistry (IHC), FISH, and DSISH.

RESULTS

The HER2-positive rate was 13%. The consistency between FISH and DSISH results was high (99%; κ = 0.958; P < 0.001). Tumor heterogeneity and polysomy were the main reasons for inconsistency. There was no significant difference in the 3-year overall survival (OS) between HER2-positive and -negative patients (P = 0.959). Multivariate analysis showed that HER2 was not an independent prognostic factor.

CONCLUSION(S)

HER2 overexpression and amplification occur in a significant number of Chinese gastric cancer patients. Given the obvious advantages and high consistency with FISH, DSISH was superior for evaluating HER2 amplification in gastric cancer. HER2 was not a prognostic factor for gastric cancer in our study.

Population pharmacokinetics of valnemulin in swine

This study was carried out in 121 pigs to develop a population pharmacokinetic (PPK) model by oral (p.o.) administration of valnemulin at a single dose of 10 mg/kg. Serum biochemistry parameters of each pig were determined prior to drug administration. Three to five blood samples were collected at random time points, but uniformly distributed in the absorption, distribution, and elimination phases of drug disposition. Plasma concentrations of valnemulin were determined by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The concentration-time data were fitted to PPK models using nonlinear mixed effect modeling (NONMEM) with G77 FORTRAN compiler. NONMEM runs were executed using Wings for NONMEM. Fixed effects of weight, age, sex as well as biochemistry parameters, which may influence the PK of valnemulin, were investigated. The drug concentration-time data were adequately described by a one-compartmental model with first-order absorption. A random effect model of valnemulin revealed a pattern of log-normal distribution, and it satisfactorily characterized the observed interindividual variability. The distribution of random residual errors, however, suggested an additive model for the initial phase (<12 h) followed by a combined model that consists of both proportional and additive features (≥ 12 h), so that the intra-individual variability could be sufficiently characterized. Covariate analysis indicated that body weight had a conspicuous effect on valnemulin clearance (CL/F). The featured population PK values of Ka , V/F and CL/F were 0.292/h, 63.0 L and 41.3 L/h, respectively.

Enhanced connexin 43 expression following neural stem cell transplantation in a rat model of traumatic brain injury

INTRODUCTION

Reestablishment of functional networks after traumatic brain injury (TBI) has been proffered as one of the goals of neural stem cell (NSC) transplantation therapeutics. Gap junctions provide essential means for direct cellular communication by transferring small molecules and ions, which may provide insights into the interplay between grafted NSCs and host cells.

MATERIAL AND METHODS

Thirty-six adult male Wister rats were used in this study. The controlled cortical impact (CCI) model of brain injury has been performed. Seventy-two hours after CCI injury, animals were randomly assigned to two groups: PBS- and NSC- transplanted group. NSCs-transplanted group received delivery of the NSCs suspension to the cortex below the injury cavity in the ipsilateral hemisphere. At 1, 2, and 4 weeks post-transplantation, we investigated the expression patterns of gap junction-associated connexin 43 (Cx43) in the transplant site and the border of CCI by immunohistochemistry, Western blot and RT-PCR.

RESULTS

Our findings showed that Cx43 staining was significantly greater in the transplant site and the border of CCI in the NSCs-transplanted rats compared to the control rats at different time points (p < 0.01 at 1 week, p < 0.05 at 2 and 4 weeks). Significantly higher gene and protein expression of Cx43 was found in NSCs-transplanted rats compared to the control rats in the period of 4 weeks post-transplantation (p < 0.01), and remained at a higher level until 2 weeks with or without NSC transplantation.

CONCLUSIONS

It is proposed that gap junction-associated Cx43 might participate in NSCs' beneficial effects via gap-junctional coupling by which grafted NSCs integrate into host neural tissue following transplantation after TBI.

The Mechanism of Yaw Torque Compensation in the Human and Motion Design for Humanoid Robots

When a humanoid robot walks fast or runs, the yaw torque is so large that the supporting foot slips easily and the robot may become unstable. The compensation for the yaw torque is important for fast humanoid walking and many studies have been focusing on yaw torque compensation. However, the issue of humanoid robot motion design that can make the movements of the robot more human-like, as well as guarantee the stability of the robot, has not been studied in-depth. In this paper, the mechanism of yaw torque compensating for human walking is firstly studied. Then we propose a method to compensate yaw torque for a humanoid robot through the motion of the arms and waist joint based on the human yaw torque compensation mechanism and ZMP stability citation. Finally, the effectiveness of the proposed method is demonstrated by the results from the simulation and walking experiments on the newly developed BHR humanoid robot.

Gene expression profiling combined with bioinformatics analysis identify biomarkers for Parkinson disease

Parkinson disease (PD) progresses relentlessly and affects approximately 4% of the population aged over 80 years old. It is difficult to diagnose in its early stages. The purpose of our study is to identify molecular biomarkers for PD initiation using a computational bioinformatics analysis of gene expression. We downloaded the gene expression profile of PD from Gene Expression Omnibus and identified differentially coexpressed genes (DCGs) and dysfunctional pathways in PD patients compared to controls. Besides, we built a regulatory network by mapping the DCGs to known regulatory data between transcription factors (TFs) and target genes and calculated the regulatory impact factor of each transcription factor. As the results, a total of 1004 genes associated with PD initiation were identified. Pathway enrichment of these genes suggests that biological processes of protein turnover were impaired in PD. In the regulatory network, HLF, E2F1 and STAT4 were found have altered expression levels in PD patients. The expression levels of other transcription factors, NKX3-1, TAL1, RFX1 and EGR3, were not found altered. However, they regulated differentially expressed genes. In conclusion, we suggest that HLF, E2F1 and STAT4 may be used as molecular biomarkers for PD; however, more work is needed to validate our result.

Population pharmacokinetics of cefquinome in pigs

This study was performed in 145 pigs to develop a population pharmacokinetics (PPK) model by i.m. administration of cefquinome (CEQ) at the dose of 2 mg/kg in the neck muscle. Serum physiological and biochemical parameters for each pig were determined before administration. After administration, 2-4 samples were collected at random, with the sampling point evenly distributed in the three periods (<1 h, 1-4 h and >4 h). The plasma concentration of CEQ was determined by high performance liquid chromatography with UV detector. The pharmacostatistical analyses of concentration-time data, weight, age, gender, serum physiological and biochemical parameters were performed with nonlinear mixed effect modeling (NONMEM). A one-compartmental model with first-order absorption and elimination adequately described the data from the study group. The optimal random effect model of pharmacokinetics parameters was of log-normal distribution and the residual errors assumed a mixed-type model (proportional and additive) to best explain intra-individual variability. Covariate analysis showed that body weight is positively correlated with apparent volume of distribution (V/F) and body clearance (CL/F). The typical PPK parameters of Ka , CL, and V were 0.564/h, 5.15 L/h, and 1.36 L, respectively.

Jet or intensive care unit ventilator during simulated percutaneous transtracheal ventilation: a lung model study

BACKGROUND

Percutaneous transtracheal ventilation (PTV) via a jet ventilator (PTJV) is considered a rescue technique in difficult airway management. However, whether a conventional ventilator can generate adequate ventilation via PTV is not known. Our goal was to evaluate the tidal volume (V(T)) generated by a conventional ventilator during simulated PTV compared with PTJV in a lung model.

METHODS

A lung model simulating an adult lung was used. A catheter was inserted through the artificial trachea and connected to either a jet ventilator or a conventional ventilator. The direction of catheter insertion was perpendicular to the trachea, pointing towards the lung and away from the lung. The jet ventilator was operated at 344.7 kPa. The conventional ventilator was operated in the pressure mode at peak inspiratory pressures of 40-90 cm H(2)O.

RESULTS

The jet ventilator generated larger V(T) [817 (336) ml] when the catheter was pointing towards the lung than when pointing away from the lung or perpendicular to the trachea [121 (41) and 69 (24) ml, respectively, P<0.01]. With the conventional ventilator, changes in V(T) at different direction of catheter insertion were much less [222 (81) ml catheter pointing towards the lung, 229 (121) ml perpendicular to the trachea, and 187 (97) ml away from the lung].

CONCLUSIONS

Our result demonstrated that PTJV was effective only when the catheter was pointing towards the lung and requires high operating pressure. A conventional ventilator can generate reasonable minute ventilation through the transtracheal catheter less dependent on directions of catheter insertion and should be considered during emergent PTV.

Analysis of the role of hMLH1 hypermethylation and microsatellite instability in meningioma progression

We investigated a possible role of hMLH1 hypermethylation and microsatellite instability in meningioma progression. Fifty meningomas were examined for methylation of hMLH1 using a methylation-specific PCR; 43 of them were analyzed for microsatellite instability using nine microsatellite markers. Loss of heterozygosity on chromosome 22q was detected using two markers. Two atypical meningiomas showed microsatellite instability at four loci; one was methylated on hMLH1 and the other was unmethylated. Nine meningiomas were found to have methylated hMLH1; the frequencies in the different grades of meningioma were one of 20, two of 16, and six of 14, respectively. We concluded that the methylation status of hMLH1 is associated with the meningioma grade but not with microsatellite instability. Loss of heterozygosity was detected in 22 cases in at least one marker. The frequency of loss of heterozygosity increased with meningioma grade, but the tendency was not significant. The correlation between loss of heterozygosity and methylation of the hMLH1 gene was also not significant. We conclude that hypermethylation of the promoter of hMLH1 is an epigenetic change in meningiomas and is associated with the tumor grade, while microsatellite instability is an uncommon event in meningiomas.

MicroRNA-330 is an oncogenic factor in glioblastoma cells by regulating SH3GL2 gene

MicroRNAs have recently emerged as key regulators of cancers. This study was therefore conducted to investigate the role of miR-330 in biological behaviors of human glioblastoma U87 and U251 cell lines and its molecular mechanism. SH3GL2 gene was identified as the target of miR-330. MiR-330 overexpression was established by transfecting miR-330 precursor into U87 and U251 cells, and its effects on proliferation, migration, invasion, cell cycle and apoptosis were studied. Overexpression of miR-330 can enhance cellular proliferation, promote migration and invasion, activate cell cycle and also inhibit apoptosis in U87 and U251 cells. Collectively, these above-mentioned results suggest that miRNA-330 plays an oncogenic role in human glioblastoma by regulating SH3GL2 gene and might be a new therapeutic target of human glioblastoma.

Vascular endothelial growth factor participates in modulating the C6 glioma-induced migration of rat bone marrow-derived mesenchymal stem cells and upregulates their vascular cell adhesion molecule-1 expression

Bone marrow-derived mesenchymal stem cells (BMSCs) have been shown to be able to migrate towards glioma, but the molecular mechanisms responsible for this migratory behavior still require further elucidation. This study aimed to test the role of vascular endothelial growth factor (VEGF) in the C6 glioma-induced migration of BMSCs, evaluate the effect of VEGF on the migratory capacity and vascular cell adhesion molecule-1 (VCAM-1) expression of BMSCs and explore the role of VCAM-1 in the VEGF-induced migration of BMSCs. The results showed that C6 glioma cells significantly increased the migration of BMSCs in vitro, which was partially blocked by a VEGF neutralizing antibody, and 20 ng/ml recombinant rat VEGF(164) incubation enhanced the migration of BMSCs. Moreover, 12 h of 20 ng/ml VEGF(164) incubation upregulated the VCAM-1 expression of BMSCs and the blocking of VCAM-1 reduced the VEGF(164)-induced migration of BMSCs. The data also revealed that LY294002, an inhibitor of phosphoinositide-3-kinase (PI3K), decreased the VEGF-induced migration and VCAM-1 expression of BMSCs. These findings indicate that VEGF participates in mediating the C6 glioma-induced migration of BMSCs by upregulating their VCAM-1 expression, and that PI3K is involved in the signal transduction of VEGF(164)-induced migration and VCAM-1 expression of BMSCs.

Inhibition of c-Jun N-terminal kinase prevents blood-brain barrier disruption and normalizes the expression of tight junction proteins clautin-5 and ZO-1 in a rat model of subarachnoid hemorrhage

BACKGROUND

The c-Jun N-terminal kinase (JNK) proteins are encoded by three genes (JNK1, JNK2, and JNK3), giving rise to multiple isoforms via alternative splicing. JNK inhibition using a chemical inhibitor SP600125 confers neuroprotection in an animal model of subarachnoid hemorrhage (SAH). The aim of this study is to investigate whether the protective effects of SP600125 were associated with modulation of tight junction proteins including claudin-5 and ZO-1 and to define which JNK isoforms were involved in the early brain injury after SAH.

METHODS

Seventy-five male Sprague Dawley rats (weighing 300-350 g) were randomly assigned to five groups (n = 15): (1) sham, (2) SAH, (3) SAH + DMSO (dimethyl sulfoxide), (4) SAH + 10 mg/kg SP600125, and (5) SAH + 30 mg/kg SP600125. SP600125 or DMSO was injected intraperitoneally 1 h before and 6 h after the induction of SAH. Animals from all the groups were killed 24 h after SAH, and brain tissues were dissected and subjected to electron microscopic examination, Western blot analysis, and histological evaluation.

RESULTS

SP600125 pretreatment restored tight junctions and attenuated blood-brain barrier (BBB) disruption and cerebral edema after SAH, coupled with reduced apoptosis in the cerebral cortex. SP600125 exposure restored the reduced expression of both claudin-5 and ZO-1 following SAH and normalized the levels of JNK1 and JNK3.

CONCLUSION

Our data demonstrate that the JNK signaling plays an important role in the regulation of tight junction proteins and BBB integrity, and thus represents a promising target against brain injuries after SAH.

Gpnmb/osteoactivin, an attractive target in cancer immunotherapy

Cancer is a complex disease with interactions between normal and neoplastic cells. Since current therapies for cancer largely rely on drugs or radiation that kill dividing cells or block cell division, these treatments may have severe side effects on normal proliferating cells in patients with cancer. Recently, immunotherapeutic approaches for cancer therapy, by which monoclonal antibodies (Mabs) target tumor specific antigens, have shown great potential. Glycoprotein non-metastatic melanoma protein B(Gpnmb)/Osteoactivin (OA) is a transmembrane glycoprotein highly expressed in various types of cancer. Gpnmb/OA promotes the migration, invasion and metastasis of tumor cells. CR 011-vcMMAE is a Mab-drug conjugate being developed for the treatment of Gpnmb/OA-expressing cancers. Gpnmb/OA represents an attractive target in cancer immunotherapy and CR011-vcMMAE holds promise as a reagent in targeted therapy for Gpnmb/OA-expressing malignancies.

Action of db-cAMP on the bystander effect and chemosensitivity through connexin 43 and Bcl-2-mediated pathways in medulloblastoma cells

Medulloblastoma (MB) is one of the most common malignant brain tumors of childhood and is associated with a poor prognosis. Gap-junctional intercellular communication (GJIC) is an important mode for cell-to-cell communication. Dysfunctional GJIC is exhibited in most cancer cells. There is significant evidence that GJIC is important in at least some prodrug/suicide gene systems by augmenting the bystander effect (BE). GJIC is made up of connexins (Cxs), among which Cx43 is present in most tissues. Bcl-2, an important apoptosis blocker, is closely associated with the sensitivity to anticancer drugs. Our study showed that dibutyryl cyclic adenosine monophosphate (db-cAMP) upregulated the Cx43 expression and GJIC function in Daoy medulloblastoma cells. It directly enhanced the BE using a herpes simplex virus thymidine kinase (HSV‑tk)/ganciclovir (GCV) system, which was blocked by a Cx43 inhibitor. In addition, db-cAMP increased the cytotoxicity of temozolomide and teniposide, possibly by downregulating the Bcl-2 expression and inducing apoptosis. Taken together, we demonstrated the beneficial effect of db-cAMP in treating medulloblastoma depending on the upregulation of BE and chemosensitivity through Cx43 and Bcl-2-mediated pathways.